Emergency draining mechanism for the centrifugal spreader of an airplane

ABSTRACT

A powdered material hopper or container is mounted in an airplane with a downwardly facing discharge opening positioned immediately above a centrifugal material discharge wheel driven by a hydraulic motor positioned in the outer end of a pivotal support in the form of a pivotal hollow housing. The pivotal hollow housing can be pivoted between a first position in which the centrifugal material discharge wheel is adjacently facing the discharge opening of the container and a second position remote therefrom for permitting a rapid emergency dumping of all material from the container. Movement of the pivotal support means is effected by a hydraulic cylinder connected to the pivotal support means and a lug extending from the lower end of the container which also provides pivotal support for the pivotal support means.

The present invention relates to an emergency draining mechanism of theairplanes transport container operated in connection with a centrifugalspreader of powdered or granular materials (fertilizers or the like),said spreader being provided with hydraulic transmission.

BACKGROUND OF THE INVENTION

Fertilizing flights and the like generally take off from temporaryfields and use low flying altitudes. Such circumstances may lead tohazardous situations in which quick reduction of weight could preventthe accident. A centrifugal type of spreader unit is provided with atransport container and closing means at the lower end thereof as wellas a centrifugal wheel with its driving device at the bottom. Thematerial to be spread will have to pass through the blade passages ofsaid wheel which passages, even with the closing means open, limit thedraining rate. Prior known with a spreader, provided with mechanicaltransmission, is a pneumatic controlled emergency draining mechanism bymeans of which the spreader is removed from the container and droppedoff the airplane, whereby the container discharges freely. On the otherhand, for the spreaders operating with hydraulic transmission there hasnot been developed a corresponding, sufficiently simple drainingmechanism and therefore the equipment used at present are not fittedwith it.

The object of the invention is to improve flying safety by means of anappropriate, simple and reliable emergency draining mechanism which canbe fitted to a hydraulic centrifugal spreader.

SUMMARY OF THE INVENTION

For this object, in the present invention a centrifugal wheel, togetherwith its drive motor, is secured to a separate housing portion (makingup a centrifugal unit together) journalled upstream of the spreader to ahorizontal pivot. The latter is mounted on the upper structure of thespreader comprising closing and control devices for the material to bespread. The centrifugal unit is held in the operating position by ahydraulic working cylinder or a like element connected between said unitand the upper structure, by means of the pressure of a medium trappedtherein. Emergency draining is triggered by discharging pressure out ofthe cylinder e.g. by means of a valve, the centrifugal unit being freeto swing under the effect of the material and its own weight obliquelydown thus opening a free draining passage past the centrifugal wheel.The operation is also possible during the take-off run as the swingingmotion is limited according to ground clearance of the airplane. Thecontainer draining can be intercepted at any time by means of theclosing members, whereby the amount of material wasted need not exceedthat necessary to clear the hazardous situation. The centrifugal unit isbrought to operating position by closing said valve and by allowingpressurized medium into the cylinder. The simplest way of doing this isto pass the medium into the cylinder from the pressure pipe of thecentrifugal wheel motor through a check valve. At the same time, thereis gained the advantage that possible cylinder and valve leaks arecompensated for when the hydraulic motor is running, thus avoiding apositional error of the centrifugal unit.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a typical position of a centrifugal spreader on an airplanein side view,

FIG. 2 is a sectional side view of a spreader with the centrifugal wheelin operating position to which the invention has been applied, and

FIG. 3 is a partial section of the device of FIG. 2 in the emergencydraining position.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Material drains from a container or hopper 1 as controlled by closingflaps 2 through a guide chamber 3 forming the lower extent of thecontainer and having a downwardly facing discharged opening whichdischarges material from the container onto a centrifugal wheel 4 whichis driven by a hydraulic motor 5 and thus hurls said material over awide range (FIG. 2). Wheel 4 and its motor 5 are mounted on a hollow,curved housing portion 6 which contains and protects motor 5 and itshydraulic hoses, not shown in the figures. Their entry in the bottom 8of an airplane is sealed with an elastic bellows joint 9. Housing 6 ishinged by means of a horizontal pivot 7 to lugs 10 fixed on the chamberportion 3. The centrifugal unit 4, 5, 6 is held in the operatingposition by a cylinder 11 by means of pressurized fluid trapped behindthe piston. The entire spreader assembly is secured to the container 1by a flange joint 12. Emergency draining is effected by turning theflaps 2 into the vertical position (FIG. 3) and by draining the fluidfrom cylinder 11 through a shut-off valve, not shown. Thus, thecentrifugal unit 4, 5, 6 descends into the position shown in FIG. 3 andmaterial flows freely past the centrifugal wheel 4 directed backwards byair stream. Propeller blast produces suction effect in the downstreamexpanding gap between the centrifugal wheel 4 and chamber 3, thusfurther increasing the container draining rate. The centrifugal unit 4,5, 6 is returned to the operating position by passing pressurized mediuminto cylinder 11 as described above.

The invention is not limited to the above-described embodiment but canbe modified within the scope of the accompanying claims.

We claim:
 1. An aircraft mounted system for dispensing granular orpowdered material including:a container for holding granular or powderedmaterial, said container having a lower downwardly facing dischargeopening; pivotal support means mounted on a pivot fixedly positionedwith respect to said container for pivotal movement between a firstposition in which an outer end of said pivotal support means ispositioned immediately adjacent and beneath said discharge opening ofsaid container and a second position spaced away from said dischargeopening; a centrifugal dispensing wheel mounted on said outer end ofsaid pivotal support means so as to adjacently face said dischargeopening to receive granular or powdered material therefrom when saidpivotal support means is positioned in said first position; motor meanssupported on said pivotal support means for drivingly rotating saidcentrifugal dispensing wheel; and power means for moving said pivotalsupport means to its second position so as to move said centrifugaldispensing wheel to a position remote from said discharge opening topermit a rapid emergency release discharge of substantially all granularor powdered material in said container.
 2. The system of claim 1 whereinsaid motor means is a hydraulic motor.
 3. The system of claim 2 whereinsaid power means is a hydraulic cylinder.
 4. The system of claim 3wherein said pivotal support means comprises a hollow curved housing. 5.The system of claim 4 wherein said motor is fully enclosed in saidhousing.
 6. The system of claim 5 additionally including pivotal controlflaps mounted inside said container for varying the rate at whichmaterial can be discharged from said container.
 7. The system of claim 6wherein said pivotal support means is mounted on an outer end of lugmeans connected and supported at an opposite end to a lower portion ofsaid container.
 8. The system of claim 7 wherein said hydraulic cylinderis pivotally supported on said lug means and has its rod end connectedto said pivotal support means.
 9. The system of claim 1 wherein saidmotor means is a hydraulic motor, said pivotal support means is a hollowhousing and said motor is enclosed in said hollow housing.
 10. Thesystem of claim 9 wherein said pivotal support means is mounted forpivotal movement about an axis positioned forwardly of said container.